Background: The development of new technologies, changes in the functioning of the economy in national and international space, growth in the financial sector place increasing pressure on the man´s ability referred to as “a financial literacy". Our study aims to find out if and how does the level of financial literacy of young people change during their study of the secondary grammar school. (2) Methods: The research methodology is based on the questionnaire survey, in which the solution of the four model situations was asked. We focused on three age groups of students: the first included the students of the second year of study. The second group included the students of the fifth year of study, and the third group included the students of the eight years of study. (3) Results: The results did not confirm an increasing level of financial literacy depending on the length of study. (4) Conclusion: The level of financial literacy does not change during the secondary school study. Limitation of the results lies in the number of respondents and only one type of secondary school and also in the model situation, which tests the students´ ability to make financial decision.